[Doom] Invulnerability animation: full bright sync, apply tic rate

The focus on the Doom invulnerability filter using Dday's first ever view shader, for 1.13's release has made me notice:

While Dday has changed the screen filter to fade in smoothly rather than instantly appear versus Vanilla, that it hasn't done the same to the full bright part of invulnerability; that still instantly occurs and it actually does it an instant before the screen filter even appears, which looks a bit ugly visually.

I would like to make an RFE that the full bright part occur smoothly, rather than instantly, to match the changes Dday made to the filters appearance?

While I'm here, I'll also point out, that in older versions of Dday, the invulnerability screen filter's fade in/out, was affected by the tic rate. In 1.13 it isn't; I'm not sure whether that is a bug or a deliberate change?